"Christian McArdle" wrote in message
et...
Well leaving aside the issues of floor weight, if you cross joist the
loft with substantial timbers (at least 4x2. maybe 5x3 or 6x3 with long
section vertical) and actually screw (DO NOT NAIL into a flexible
ceiling - it WILL crack the plaster) every joist where they cross,

Another alternative, if joists are deep enough for strength, but not
enough
for your insulation is to use rigid foam insulation between the rafters
and
fill the joists to whatever depth is available before boarding. You do
need
to consider ventilation. The space behind the insulation in the rafters
will
probably need ventilating, although this is not necessarily a given if
there
is no felt or sarking.

The advantages of this method is that it turns the loft into a better
climate and doesn't require changes to the joist structure. If the rafter
and joist insulation is of the same value, the temperature will be about
halfway between the house and the outside temperature, making it ideal for
storage.

Unfortunately it's also got 100% of the moisture which may condense in this
area - over the storage. So a good vapour barrier and a sealed loft hatch
is essential.